The present research proposal is directed toward the chemical synthesis of glycosides of biological importance. Diverse protecting groups such as benzyl, allyl, chloroacetyl and other groups will be utilized in our investigations. Different glycosylating reagents such as oxazolines, 1,2-0-alkyl orthoesters and 2,3-0-carbonyl substituted-alpha-D-mannopyranosyl halides, containing persistent and temporary protecting groups will be efficiently prepared and further employed in the sequential synthesis of complex saccharides. Halide ion catalyzed reaction will be applied for the preparation of desired 1,2 cis linked glycosides. The scope of silver triflate as catalyst in the glycosylation reaction with certain halides will be examined in the proposed studies. We plan to employ organotin derivative as the key intermediate for selective alkylation of equatorial hydroxy group in vicinal equatorial-axial pair. Generally, the aglycons having persitent protecting groups on other hydroxy groups will be employed as the starting material for the synthesis of higher saccharides. In the proposed studies, attempts will be made on the isolation of the pure material after each step of a chemical reaction, if possible. Preparative t.l.c. technique may have to be utilized for the purification of some of the compounds. T.l.c. of a compound will be performed in a number of different solvent systems in order to establish its absolute purity. Paper chromatography will be extensively used for the confirmation of the purity of the free saccharides. G.l.c. technique will further establish the homogeneity of the di- and trisaccharide derivatives and if possible including tetrasaccharides. The synthetic compounds may also be characterized by their n.m.r. and infra-red studies.